Night at the historic Lowell Observatory in Flagstaff, Arizona. Lowell Observatory was established in 1894 by Percival Lowell, placing it among the oldest observatories in the US, and is designated a National Historic Landmark for prominent astronomical discoveries made here including discovery of Pluto by Clyde Tombaugh in 1930. The Observatory's original 24-inch refractor telescope (pictured here) is still in use today for education and public observation. Dennis Mammana, Dennismammana.com